1-tetrahydrofuryl-3, 6, 9-nonanetriol trialkanoates



tries l-TETRAHYDROFURYL-3,6,9-NONANETRIOL TRIALKANOATES Charles R. Russell, Peoria, and Lester E. Schniepp, Barrington, 11]., Louis S. Hefner, Indian Head, Md, and Herbert E. Smith, Peoria, 111., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Application July 25, 1957 Serial No. 674,259

Claims. ((11. 260-4414) (Granted under Title 35, U. S. Code (1952), see. 266) 0 OCOCL'HS 0002115 OOCZHE and hereinafter identified as Compound 1;

l-tetrahydrofuryl-3,6,9-nonanetriol tributyrate having the formula ens-on. cg: oH-om-ormon-cnz-orrz-on-cnrorn-on.

O OCOCaH'; COC3H7 OOOCKHI and hereinafter identified as Compound 2;

l-tetrahydrofuryl-B,6,9-nonanetriol tricaproate having the formula C H2-C Ht oH-t oH-om-om-cH-oHr-CfirOH-CHz-CHr-OH.

O OCOCsHn OCOCsHn OCOCsHu and hereinafter identified as Compound 3;

And 1 teunhydrofuryl 3,6,9 -nonanetriol tricaprylate having the formula and hereinafter identified at Compound 4.

These esters are liquid and remain so even at exceedingly low temperatures (that is, have low pour points), are essentially non-volatile so that there is no evaporation of the liquids from lubricated bearings even when these are subjected to elevated temperatures, they are stable compounds and hence do not decompose when subjected to elevated temperatures as in overheated bearings or the like, and they exhibit superior lubricating activity over a wide temperature range as shown by their ASTM viscosity slopes and kinematic viscosity indexes. as low temperature lubricants, e. g., in internal combustion engines. They also find utility as plasticizers in polyvinyl resins.

Data illustrating these properties is given in the fol lowing tables wherein Table I lists the boiling and pour points and Table 11 lists the viscosity-temperature characteristics of the esters.

These properties make them admirably suitable atent C Table l BOILING POINTS AND POUR POINTS or THE ns'rnns Boiling point Pour point Ester or melting Temp., Pressure, point, F.

C. pHg

Compound 1. 40. 0 -41. 8 Compound 2. 150 4. 0 61. 1 Compound 3 5.0 65. 2 Compound 4 200 2.0 58. 0

Table II VISCOSITY TEMPERATURE CHARACTERISTICS OF ESTERS Viscosity (cs.) Kinematic Ester A. S. T. M. viscosity ope index 210 F. 100 F.

Compound 1 4. 66 31. 45 0. 793 50. 3 Compound 2 4. 71 26. 60 0. 743 104. 7 Compound 3 5. 54 31. 79 0.720 122. 5 Compound-4 6. 85 40. 91 0. 676 131.0

A number of the esters were evaluated as plasticizers in polyvinyl resins and found to be generally equal to dioctyl phthalate, and were definitely superior at low temperatures (70 F.). For example, they may be incorporated in amounts up to 40 percent or higher in Vinylite VYHl-I (a typical lacquer-type polyvinyl chloride-acetate resin) and Geon 121 (a typical polyvinyl chloride resin used in plastisol formulations). The former gave films equal in strength to dioctyl phthalate plasticized films, and some were superior in compatibility while others were only slightly inferior. In the Geon 121 formulations, all the novel plasticizers tested gave softer specimens than did dioctylphthalate, and all passed the 70 F. brittleness test (loop method) whereas a specimen formulated with dioctylphthalate failed.

The esters of the invention maybe prepared by esterifying the required triol with theappropriate acylating agent. The process which we have employed, in most cases, has been to heat the reactants, dissolved in an inert non-aqueous solvent such as benzene, in the presence of a catalytic amount of an acidic catalyst such as p-toluenesulfonic acid. The course of esterification may be followed by separating the water of reaction in such a manner as to enable observation of its rate and quantity.

The trihydroxyalkanes used as starting materials in this invention, and methods for their preparation, are disclosed in a paper by C. R. Russell, K. Alexander, W. O. Erickson, L. S. Hafner, and L. E. Schniepp published in Jour. Am. Chem. Soc. 74, 4543 (1952).

EXPERIMENTAL Table III, below, shows the characteristic physical properties of the triesters of this invention, and the methods by which they may be made. It is to be understood, however, that other methods of carrying out the esterification may be employed, as for example by ester interchange as disclosed in U. S. Patent No. 2,476,052.

Preparation of estersGeneral pr0cedure.-From 0.3 to 0.5 mole of the respective triols and an excess of the acids indicated in the table were dissolved in 200 ml. of benzene and 2 g. of p-toluenesulfonic acid added. The reaction mixture was heated to reflux and the course of the reaction followed by the rate of water collection in a separating device attached between the flask and the reflux condenser. When water collection ceased the less than that calculated as necessary to neutralize the catalyst and excess acid. The remaining acid was removed by extraction with percent sodium bicarbonate solution. The benzene layer was washed to neutrality with distilled water and then dried over anhydrous magnesium sulfate.

With the products from the higher molecular weight fatty acids it was necessary to add some n-butanol to break up emulsions and facilitate removal of the soaps which formed during these extraction operations. 7

The dry benzene solutions were filtered and the solvent removed by distillation on a steam-bath. Last traces of solvent and low boiling impurities were removed by heating on a steam-bath under reduced pressure. The crude esters were purified by the methods indicated in Table III. The yields shown in Table III for the once distilled esters are probably l0+% low because of the large holdup in the falling-film type molecular still.

Cir

with the boiler completely immersed in an electrically heated oil-bath. A very fine capillary extending to the bottom of the boiler prevented bumping. The use of a fraction cutter permitted the collection of up to five fractions without interrupting the distillation. In addition to its use for complete distillation of some esters, this still was also used for stripping out traces of acids and other low boiling impurities prior to distillation in the falling-film molecular still. This was done by heating the material in the still under high vacuum to a temperature just below the boiling point or, for the higher boiling esters, to a bath temperature of 200". These conditions were maintained until no more volatile materials were collected.

Extraction-In several cases the complete removal of monoand di-esters could not be accomplished by distillation alone. These impure esters were dissolved in heptane and the heptane solutions extracted several times Purification r nerfzods -The once distilled esters were withvarious concentrations of aqueous ethanol. Such reprocessed as necessary to bring their physical properextractions are indicated in Table III.

Table III Properties of purified esters Triol, Acid, Time, Yield,- Purifica- Distillation Ester moles moles hrs. percent tion method as wa 1 Temp, Pres- (l sure 0. 4 1. 8.0 63 175 40. 0 1. 4566 l. 040 0. 4 1. 50 8.0 66 150 i. 0 1. 558 1.008 0.3 1. 05 13. D 56 180 0 1. 4573 it 983 ll?) 1.05 14.0 54 i 200 2.0 1.4596 0.954

Properties of purified esters-Continued I Analyses e Saponification Ester Mn b equiv. Free acid, Empirical Carbon Hydrogen performula cent Calcd., Found, Calcd, Found. Ca-led Found Oalcd Found percent percent percent percent Cornpo'undl 108.27 108.74 138.2 139.0 0. 59 022113501 63.74 63.5 9.24 9.45 Compound 2 122.13 123. 152. 2 153. 8 0.07 CzaHuO1 65. 65. 9 9. 71 9. 81 Compound 3. 149. 85 150. 16 180. 3 182. 3 0. 59 CzuHsaO1 68. 83 68. 5 10. 43 10. 28 Compound 4 177. 57 179. 44 208. 3 211. O 0. 20 (13 11 07 71. 10 71. 2 10. 96 10.

Calculatd on the 'basis of the once distilled product having an analytical purity of 95+ All distillations except wer car'rledtout onthe, falling-film still.

b Observed on final distill ion; temperature of the hot finger of the falling-film still; vapor temperature in alembic flask still. 'lvteasured by MeLeodnnd calibrated thermocouple gauges attached between still and solid 00; cooled trap.

5 Measured byFischer-Davidson gravitometer.

e Calculated from 'n aud'd values determined at 20.

Distilled in falling-film molecular still. 8 Distilledin'alembic. flask still.

Stripped of low boiling impurities in alembic flask still. i Heptane solution extracted with 60% aqueous etlienol. i Heptane'solutlon extracted with 85% aqueous ethanol.

ties to a state of constancy and 'the analytical data into accord with calculated values. These purification steps and the order in which they were applied are indicated in Table III. 7 V

Distillation-Two types of apparatus were used for the purification of these products by distillation. Most of the esters were distilled at least once in a falling-film type molecular still equipped with a magnetically operated pumping device for recycling undistilled material. This still was also fitted with a fraction cutter which permitted the collection of three fractions without interrupting the course of the distillation. The still unit was attached to a manifold which was connected to a mercuryvapor pump backed by aneflicintmechanical pump. All samples were degassed at at 10 to 50 for 1 hour before transferring them to the still. 7 V

The second type of apparatus was an alembic flask still similar in design to the still described by J C. (Iowan, L. B. 'Falkenburg, and H. M. Teeter, Ind. Eng. Chem, Anal. Ed.,' 16 50 (1944). This still was operated We claim: 1. 1-tetrahydrofuryl-3,6,9-nonanetriol tricaproate having the formula 5 ing the formula CH2-GH2 CE: /C'H-CHrOHrCH-CHrGHz-CH-CHz-CHz-CH:

O OCOCvHis COCrHrs COC7His '3. 1-tetrahydrofuryl-3,6,9-nonanetriol tributyrate having the formula OH:-OH2

C52 /CH-CHaCHr-CE-CHz-CHz-OH-OHz-CHg-CH:

O CO Call: 0 GOC3H1 COCIHI 4. 1 tetrahydrofuryl 3,6,9 nonanetriol tripropionate having the formula CH -CHz g: /CH-CHz-CHz-CH-CHz-CHz-CH-OHr-CHz-CHz 5 COCzHa OCOC2H5 COCzHs 5. A compound selected from the group consisting of 1-tetrahydrofuryl-3,6,9-nonanetriol tripropionate having the formula C H2(|3 2 Ogz /CH-CHz-CHz-CH-GH7OHrCH-CH -CHrOHQ O OCOCzHs OGOCaHa OCOCzHs 1-tetrahydrofuryl-3,6,9-nonanetriol tributyrate having the formula C H2-?Hg I39 CH-CHrCHrCH-CHz-CHz-CH-CHz-CHz-CH: 2O

0 (3008117 0003117 $COQ3H7 6 1-tetrahydrofuryl-3,6,9-nonanetrio1 tricaproate having the formula CH P-CH CH OH-CHz-CHg-CH-CHz-CHz-CHCHg-CHz-CH 0 OCOC5H OCOCsHu OCOC5H11 and O OCOC7H15 COC7H15 $COC7H15 References Cited in the file of this patent FOREIGN PATENTS Germany Nov. 13, 1931 OTHER REFERENCES Cohen et 211., Ind. and Engr. Chem. :1766-1775 (1953). 

5. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 1-TETRAHYDROFURY-3,6,9,-NONANETRIOL TRIPROPIONATE HAVING THE FORMULA 